Sensitive fluorescent detection of DNA probes is required for applications such as DNA sequencing, in situ hybridization and multi-component arrays for detecting mRNA expression. Such applications are typically limited in sensitivity by autofluorescence of tissues and cells and other environmental components. Thus, there is a continuing need for highly efficient, low background fluorescent dyes in biological research and clinical diagnostics. Phase I is designed to determine the feasibility of using novel far-red and near-infrared (NIR) fluorescent labeled nucleic acids to detect the hybridization of mRNA to gene microarrays. We have chosen yeast genes and their cognate mRNAs as a suitable test system which may also have broad application in research. In Phase II we will synthesize a family of fluorescent dyes is an optimize their use with DNA and RNA probes. We will also develop the IR scanner so that the labeled probes we offer can be effectively used in the field. In Phase II the labeling conditions and use parameters of the labeled probes will be refined market for analysis of gene expression. PROPOSED COMMERCIAL APPLICATION: The near term applications of this technology are in the research market. Novel, reactive near-infrared dyes which can be directly employed to label nucleic acids can be used in fluorescence in situ hybridization (FISH), detecting mRNA expression in microarrays and potentially in labeling DNA sequencing primers.